Authorities as the decision cited them, with how this panel applied each one.
Lab. Code, § 5952(d)
Award, order, or decision must be supported by substantial evidence
Applied to review of medical evidence and apportionment
From the decision · page 4DISCUSSION
It is well established that any award, order, or decision of the Appeals Board. must be
supported by substantial evidence. (Lab. Code, § 5952(d); Lamb v. Workmen's Comp. Appeals Bd.
(1974) 11 Cal.3d 274, 281 [39 Cal.Comp.Cases 310]; Garza v. Workmen's Comp. Appeals Bd.
(1970) 3 Cal.3d 312, 317 [35 Cal.Comp.Cases 500]; LeVesque v. Workmen's Comp. Appeals Bd.
(1970) 1 Cal.3d 627, 635 [35 Cal.Comp.Cases 16].) In order to constitute substantial evidence as
to the issue of apportionment, the medical opinion must disclose the reporting physician's
familiarity with the concepts of apportionment and must delineate the approximate percentages of
permanent disability due to the direct results of the injury and the approximate percentage of
permanent disability due to other factors. (Acme Steel v. Workers' Comp. Appeals Bd. (Borman)
(2013) 218 Cal.App.4th 1137 [78 Cal.Comp.Cases 751]; Escobedo v. Marshalls (2005) 70
Cal.Comp.Cases 604 (Appeals Board en banc).) Also, the physician must explain the nature of the
other factors, how and why those factors are causing permanent disability at the time of the
evaluation, and how and why those factors are responsible for the percentage of disability assigned
by the physician. (Escobedo v.
Acme Steel v. Workers' Comp. Appeals Bd. (Borman) (2013) 218 Cal.App.4th 1137
Medical opinion must disclose familiarity with apportionment concepts and explain percentages assigned
Applied to evaluate Dr. Nathan's apportionment opinion
From the decision · page 4DISCUSSION
It is well established that any award, order, or decision of the Appeals Board. must be
supported by substantial evidence. (Lab. Code, § 5952(d); Lamb v. Workmen's Comp. Appeals Bd.
(1974) 11 Cal.3d 274, 281 [39 Cal.Comp.Cases 310]; Garza v. Workmen's Comp. Appeals Bd.
(1970) 3 Cal.3d 312, 317 [35 Cal.Comp.Cases 500]; LeVesque v. Workmen's Comp. Appeals Bd.
(1970) 1 Cal.3d 627, 635 [35 Cal.Comp.Cases 16].) In order to constitute substantial evidence as
to the issue of apportionment, the medical opinion must disclose the reporting physician's
familiarity with the concepts of apportionment and must delineate the approximate percentages of
permanent disability due to the direct results of the injury and the approximate percentage of
permanent disability due to other factors. (Acme Steel v. Workers' Comp. Appeals Bd. (Borman)
(2013) 218 Cal.App.4th 1137 [78 Cal.Comp.Cases 751]; Escobedo v. Marshalls (2005) 70
Cal.Comp.Cases 604 (Appeals Board en banc).) Also, the physician must explain the nature of the
other factors, how and why those factors are causing permanent disability at the time of the
evaluation, and how and why those factors are responsible for the percentage of disability assigned
by the physician. (Escobedo v.
City & County of San Francisco v. Industrial Acc. Com. (Murdock) (1953) 117 Cal.App.2d 455
Medical proof required for diagnosis and causation beyond lay knowledge
Applied to dental injury claim requiring expert evidence
From the decision · page 5As to the issue of applicant's dental injury claim, it has long been recognized that evidence
from a lay witness on an issue requiring expert opinion is not substantial evidence, and medical
proof is required when issues of diagnosis, prognosis, and treatment are beyond the bounds of
ordinary knowledge. (City & County of San Francisco v. Industrial Acc. Com. (Murdock) (1953)
117 Cal.App.2d 455 [18 Cal.Comp.Cases 103]; Bstandig v. Workers' Comp. Appeals Bd. (1977)
68 Cal.App.3d 988 [42 Cal.Comp.Cases 114].) Therefore, applicant's testimony that the
medication he has been taking has affected his teeth, is not substantial evidence. As the WCJ stated
in his Report, "Dr. Dimmick does not provide an affirmative opinion about the diagnosis's
causation but suggests that further evaluations would be appropriate." (Report p.